"The Legend of Ruby Sunday" Kicks Off 'Doctor Who's' Endgame By Bringing Back a Classic Foe

If there's one thing Russell T. Davies is going to do, it's craft a big, loud, splashy two-parter to close out any season of Doctor Who he's involved in. From "Bad Wolf" and "The Parting of the Ways" back during Christopher Eccleston's tenure as the Doctor to the "The End of Time, Parts 1 and 2" double bill that closed out Davies' (and David Tennant's) first run with the show and brought back almost every character from his tenure, the man simply loves a big, dramatic showstopper of an ending. Your mileage may vary on the effectiveness of these stories' huge stakes or their frequently nonsensical resolutions, but they're always a blast to watch and often boast some of the best character moments of the season. 

In that light, it's hard to judge "The Legend of Ruby Sunday" on its own merits, given that it's so clearly just one piece of a larger whole. As episodes go, it's certainly propulsive. The hour zips by and features several deep lore callbacks and wildly cool set pieces, including something called a Time Window that we better be seeing on that UNIT spin-off we're all convinced is still happening. But there's a lot of table-setting in this penultimate installment, as the season's ongoing mysteries are brought together, fan-favorite characters like Yasmin Finney's Rose and Bonnie Langford's Mel return, and we get our first proper glimpse of the season's true Big Bad. 

That the episode ends on a fairly massive cliffhanger probably won't surprise anyone, and though it answers one of the season's biggest mysteries — sorry, guys, it's still not Susan — it still leaves plenty of questions for next week's final hour. 

"The Legend of Ruby Sunday" begins with the Doctor and companion crash landing into UNIT headquarters in the hopes of finding answers to multiple mysteries. The Doctor wants to quiz Kate Lethbridge-Stewart's team about the mysterious woman who keeps popping up along his timeline — actress Susan Twist has appeared as everything from a portrait and a sentient ambulance to a random hiker and a 1960s cafeteria worker this season — and figure out whether she might actually be his granddaughter Susan. 

Conveniently, this woman also exists on Earth in 2024, this time as an IT genius named Susan Triad, whose company, S. Triad Technology, is releasing a piece of key free software that will somehow help the world. The name of the company is immediately assumed to be an anagram for TARDIS, and UNIT has long suspected she might be of the "evil genius with secret alien technology" variety. But according to Mel, whose been undercover on her team, Susan Triad's big secret is mostly that she's...just really nice. 

The episode spends a surprising amount of time on the "Is this Susan" red herring, so much so that it's probably worth it to wonder if the question of the Doctor's granddaughter will thread throughout Davies's second tenure with the show. It is, after all, one of the franchise's last great mysteries, and this season alone has touched on the Doctor's grief over losing her at multiple points. In fact, the scene in which Kate and Fifteen discuss her father and the Doctor's guilt about never visiting his granddaughter because of the destruction he often leaves in his wake is one of the best of the season. It perfectly leans into the show's history in a way that feels rich and meaningful while not out of reach for viewers who have no idea who the Brigadier is.

But if Susan Triad isn't Susan, the Doctor's granddaughter, then who is she? And how does she fit into the story of Ruby's origins? That's a question that will have to be fully answered in the season finale, but "The Legend of Ruby Sunday" delves back into the night that Ruby was left as a foundling, using UNIT's badass Time Window — and a little help from the VHS CCTV recording from her birthday — to recreate the moment her mother left her on the church steps. 

The results are pretty inconclusive. The tape and its recreation are grainy and unclear, and although Ruby manages to make it snow again, there's no clear view of her mother's face, and the woman appears to be shadowed or shielded in some way. It's a relatively traumatic emotional experience for Ruby. Also, it seems to invite the appearance of a monstrous void, which wraps itself around the TARDIS, kills a UNIT officer by essentially desiccating his body,  and speaks with a dead man's voice that basically confirms it's somehow connected to the mysterious One Who Waits we've been expecting to meet since David Tennant special "The Giggle." 

Why Rose isn't immediately suggesting calling her Uncle Fourteen at this point is a mystery, but instead, Fifteen races off to interrogate Susan Triad. She may not be his Susan, but she has had strange dreams about alien planets, strange daughters, and inexplicable versions of herself with robot faces and White Walker eyes. As she begins to break down, the stories of Susan and Ruby intertwine, and she begins to speak in the voice of a monster—a monster who is somehow actually the God of Death. 

So convinced this mystery was about him, Fifteen missed the fact that UNIT has employed a woman with the literal name of Harriet Harbinger — sent to warn humanity of a God's coming — and the anagram for Susan's company wasn't TARDIS, it was Sutekh. Surprise, the God of Death has arrived to destroy the world, possessing Susan Triad's body and manifesting a large Cerberus-like beast in the middle of UNIT HQ. And that, kids, is what we call a proper cliffhanger. 

This season has leaned into the idea of The Pantheon, a group of powerful gods who exist outside of time and beyond the Doctor's ability to defeat. We've met several already: the aforementioned Toymaker, God of Games, and Maestro, God of Music. Harriet the Harbinger runs down an intriguing list of other powers, including the Trickser, the God of Traps; Reprobate, the God of Spite; the threefold deity of Malice, Mischief, and Misery; and the Gods of Disaster, Doubt, and Dread. 

Will we be seeing any and/or all of the rest of these beings in the finale? Odds are good we may meet at least one more, given that it's evident that Ruby's neighbor, Mrs. Flood, knows a lot more about this than she's ever let on. (Sorry to everybody, including me, who was hoping she was Romana or The Rani.) Is she herself a god of some type? A child of the Toymaker? Stay tuned.

What makes this twist super fun, however, is how much of a deep cut it actually is. For all that Disney and Davies have hyped about the fresh start nature of this particular season of Doctor Who, it's wild that we're suddenly throwing it back to a villain from the Fourth Doctor era. The Fourth Doctor and companion, Sarah Jane Smith, encounter Sutekh in the Classic Who story "The Pyramids of Mars," in which an archeologist accidentally unleashes an alien evil that wants to destroy all life in the cosmos. Also known as Sutekh the Destroyer, the villain was ultimately defeated by the Doctor, though readers of the Doctor Who comics know he was allegedly rescued by his son Anubis and could very well have been waiting since then for his chance at revenge.

How — or even if — the show will address the Doctor's past with this particular villain is a question we'll have to let the finale answer, but it's an intriguing connection to the show's past in a way that most of us didn't expect.

New episodes of Doctor Who stream on Friday evenings on Disney+ in the U.S. and midnight on Saturday mornings in the U.K.